<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        'use strict';
        var a=typeof '你好，世界';
        console.log(a);//string
        var b=typeof 123;
        console.log(b);//number
        var c=typeof true;
        console.log(c);//boolean
        var d=typeof NaN;
        console.log(d);//number
        var e=typeof Math.max();
        console.log(e);//number
        var f=typeof Math.abs;
        console.log(f);//function
        var g=typeof undefined;
        console.log(g);//undefined


        var aa=typeof [1,2,3,4,5,6];
        console.log(aa);//object
        var bb=typeof {name:'娜娜'};
        console.log(bb);//object
        var cc=typeof null;
        console.log(cc);//object


        //new 包装对象
        typeof new Number(123); // 'object'
        console.log(new Number(123) === 123); // false

        typeof new Boolean(true); // 'object'
        console.log(new Boolean(true) === true); // false

        typeof new String('str'); // 'object'
        console.log(new String('str') === 'str'); // false
    </script>
</body>
</html>